1. Field of the Invention
This invention relates to improvements in free flow conveyors, and more specifically to a free flow conveyor in which roller chains are incorporated to define an upper coveying path in common with another one therebelow so as to simplify the system thereof and to reduce the driving energy required.
2. Description of the Pior Art
In order to convey pallets freely loaded on a pair of roller chains which respectively travel freely on both sides of the conveying path, a free flow conveyor typical of the prior art has been favorably employed in a production line for electrical components. In such a free flow conveyor typical of the prior art, the conventionally basic mechanism, as shown in FIG. 1, comprises an upper conveying feed path 10 for the pallets, a conveying return path 12 for the pallets therebelow, sprocket members 14a, 16a, 14b, and 16b mounted within each conveying path with endless roller chain members 18, 20 respectively wound thereon, and separately equipped motor members 22, 24 for independently driving the roller chain members 18, 20. Referring to FIG. 1 in particular, shown therein and designated by reference numeral 26 are the pallets which are freely loaded on the roller chain members 18, 20, and designated by the numerals 28, 30, respectively, are elevator members for transferring the pallets at both terminal ends of the conveying feed path 10 and the conveying return path 12. The elevator members 28, 30 have their own endless roller chain members 32, 34, respectively, for supporting the pallets. For example, initially, after the endless roller chain 32 of elevator mechanism 28 has received the pallets which have been conveyed on the conveying feed path 10, the elevator 28 is lowered to the level of the conveying return path 12, and secondly, the roller chain 32 is fed in the counterclockwise direction so as to transfer the pallets 26 to the conveying return path 12. The pallets 26 conveyed onto the conveying return path 12 are then transferred to the other endless roller chain 34 of elevator mechanism 30, after which the elevator 30 is elevated up to the level of the conveying feed path 10, and subsequently, the pallets are transferred to the conveying feed path 10 by clockwise movement of the endless roller chains 34.
Such being the foregoing case with the conventional free flow conveyor, however, the mechanism of moving the endless roller chains independently for each conveying path, and of providing separately equipped driving motors may lead to considerable disadvantages which include not only the need for an intricate mechanism and an increasing number of component members, but large operating costs due to the large amount of driving energy required.